Watermelon shown to boost heart health

Eating an apple a day may keep the doctor away, but eating
watermelon may just keep the cardiologist at bay.

A study from Purdue University and the University of
Kentucky showed that mice fed a diet including watermelon juice had lower
weight, cholesterol and arterial plaque than a control group. The findings,
reported in the Journal of Nutritional Biochemistry, suggest that
citrulline, a compound found in watermelon, plays a role in cardiovascular
health.

"We were interested in citrulline because previous
studies showed that it may lower blood pressure," says Shubin Saha, a
Purdue Extension vegetable specialist and study co-author. "We didn't see
a lowering of blood pressure, but these other changes are promising."

The researchers fed two groups of mice diets high in saturated
fat and cholesterol. Half the mice received water containing 2% watermelon
juice, while the others received the same amount of water supplemented with a
solution that matched the carbohydrate content of the watermelon juice.

The mice that consumed watermelon juice gained about 30%
less weight than the control group and had about 50% less LDL cholesterol—the
so-called bad cholesterol. The experimental group also had about a 50%
reduction in plaque in their arteries, as well as elevated levels of
citrulline.

"We know that watermelon is good for health because it
contains citrulline," says Sibu Saha, a professor of surgery at the
University of Kentucky. "We don't know yet at what molecular level it's
working, and that's the next step."

The scientists are interested in finding a secondary market
for watermelons in nutraceuticals, which are foods or food components that also
offer health benefits. Shubin Saha said that about 20% of each year's
watermelon crop is wasted either because the fruit is visibly unappealing to
consumers or because some growers find it too expensive to pay for harvesting
as prices drop during the height of watermelon season.

"We could use the wasted melons that can't go to market
for extracting beneficial compounds," Shubin Saha says. "Growers are
putting energy into these crops, so if we can do something to help them market
their additional product, that would be a benefit to the industry and
consumers."

Shubin Saha says he would continue to look at how
concentrations of citrulline and lycopene, another compound found in
watermelon, affect health. He will also test other varieties to determine
whether particular watermelons have more health benefits.